1. Field of the Invention
This invention relates to a palletizing system and more particularly to such system for palletizing a plurality of cartons of relatively fragile material such that the weight of the upper cartons is not imposed on the lowermost cartons.
2. Description of the Prior Art
Advantages of the invention can be best appreciated in the context of prior art procedures employed in processing and shipping head lettuce. It has been the typical procedure for field hands to cut growing lettuce heads, remove the outer leaves from the heads, and place the heads in parallelepiped cartons which are sized to receive 24, 32, 40 or 52 heads of lettuce depending on the size of the heads and the size of the carton. Thereafter, the cartons are loosely stacked on a pallet for transport. In order to avoid crushing the heads on the lowermost tier of cartons, the stack on the pallet is typically limited to 4 or 5 tiers. The pallet loaded as described above is then transported to a vacuum cooler, loaded into the cooler for vacuum cooling and removed therefrom when cooling is completed. Thereafter, the cartons are removed from the pallet one-by-one and conveyed to a refrigerated vehicle, such as a semi-trailer or railroad car. The individual cartons are then loaded into the vehicle for shipment to their destination. In following the prior art procedure labor costs are substantial.